# How do you visualize a ROC curve?

## How do you visualize a ROC curve?

To plot the ROC curve, we need to calculate the TPR and FPR for many different thresholds (This step is included in all relevant libraries as scikit-learn ). For each threshold, we plot the FPR value in the x-axis and the TPR value in the y-axis. We then join the dots with a line. That’s it!

What is ROC in Weka?

What we want to measure is the area under the curve. It’s called an ROC, “Receiver Operating Characteristic”, curve, for historical reasons. Weka prints out the area under the ROC curve.

Where is AUC Weka?

Under the ROC Curve
AUC = the Area Under the ROC Curve. Weka uses the Mann Whitney statistic to calculate the AUC via the weka.

### How do you combine ROC curves?

How to plot two or more ROC curves on the same graph.

1. Go to the first ROC graph.
2. Double click to bring up the Format Graph dialog.
3. Go to the middle tab.
4. Click Add to add a data set to the graph, and pick the appropriate data set (the “ROC Curve” page of the appropriate ROC analysis.
5. Repeat as necessary.

What is threshold in Weka?

For example, the typical threshold value of 0.5 means the predicted probability of “positive” must be higher than 0.5 for the instance to be predicted as “positive”. Weka just varies the threshold on the class probability estimates in each case.

What is PRC area?

Computes the area under the Precision-Recall curve (PRC). The PRC can be interpreted as the relationship between precision and recall (sensitivity), and is considered to be a more appropriate measure for unbalanced datasets than the ROC curve. The PRC is computed by integration of the piecewise function.

## How do you compare two ROC curves in SPSS?

Comparing two or more ROC curves

1. Select a cell in the dataset.
2. On the Analyse-it ribbon tab, in the Statistical Analyses group, click Diagnostic, and then under the Accuracy heading, click:
3. In the True state drop-down list, select the true condition variable.

How do you calculate ROC curve in Excel?

How to Create a ROC Curve in Excel (Step-by-Step)

1. Step 1: Enter the Data. First, let’s enter some raw data:
2. Step 2: Calculate the Cumulative Data.
3. Step 3: Calculate False Positive Rate & True Positive Rate.
4. Step 4: Create the ROC Curve.
5. Step 5: Calculate the AUC.